Conventionally, in order to prevent lightning damage, in particular, induced lightning damage, an arrester is used in electrical equipment, electronic equipment, communication equipment, control devices, communication lines, and the like using small electric power. FIG. 35 is a schematic view illustrating one example of the configuration of a conventional arrester. In FIG. 35, a conventional arrester has a gap portion 101 forming a gap and a resistor 102 serving as an energy absorber, which are connected in series. The gap portion 101 and the resistor 102 are respectively connected to electrode terminals 103 and 104. The electrode terminal 103 is connected to a lightning damage prevention line, and the electrode terminal 104 is connected to a grounding conductor. The gap portion 101 is a discharge gap where discharge occurs at the time of a high-voltage lightning strike such as induced lightning, and is sealed in a glass case. The resistor 102 is connected for absorbing energy of a lightning strike.
On the other hand, as an arrester capable of promptly absorbing overvoltage generated due to a lightning strike, an arrester also has been developed in which a discharge gap and an energy absorber are integrally formed (see Patent Document 1 etc.). FIG. 36 is a schematic view illustrating one example of the configuration of such a conventional arrester. In FIG. 36, a conventional arrester has molybdenum metals 105 and 106 on whose surfaces electrically insulating oxide films are formed. A discharge gap is formed by the oxide films of the respective molybdenum metals abutting against each other. Furthermore, the molybdenum metals 105 and 106 serve as energy absorbers. The molybdenum metals 105 and 106 are respectively connected to electrode terminals 107 and 108. When a high voltage is applied between the electrode terminals 107 and 108, electricity is discharged between the molybdenum metals 105 and 106, and thus application of overvoltage to electronic equipment or the like is suppressed. In this conventional arrester, even if a voltage between the electrode terminals 107 and 108 is a low voltage, a current flows between the electrode terminals 107 and 108 although the current is extremely small. Thus, there is an advantage in that when an excess voltage generated due to a lightning strike is applied between the electrode terminals 107 and 108, the excess voltage can be promptly absorbed.
[Patent Document 1] JP H07-118361B (pages 1 to 3, FIG. 1 etc.)